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View Full Version : ADX downsampling and 22050Hz stereo


Eiji
21-10-2007, 06:15
Why do ADX's downsampled from 44100Hz stereo to 22050Hz stereo sound so deep like they have the bass enhanced?

I'm using ADX Encode Helper which uses adxencd to encode ADX files.

http://i24.tinypic.com/2pzibd5.jpg

Here are two files to show what I mean.

http://www.sendspace.com/file/pfqjpq

Darkfalz
22-10-2007, 14:45
I have never noticed this, but some of the adx decoders I found were substandard, many completely changed the rms volume (Bero's one came to mind) or had garbled results with non 44100 files.

The most accurate one I found was ADX_Conv.exe which was an ugly GUI based decoder, but gave perfect volume levels for all sample rates. Encoding must be done with adxencd.exe and nothing else.

The method of downsampling may also make a difference, I strongly recommend sox (sox.soundforge.net) not only because it makes batch mode easy but the high quality polyphase filter is great.

Xiaopang
22-10-2007, 15:32
i always use the adx-plugin for winamp and its diskwriter plugin. the resulting wave-files sound just like the originals. darkfalz is right. use adxencd only. i tried this gui not long ago and it doesn't even work correctly. in my case, it totally ignored the channel settings.

Darkfalz
23-10-2007, 05:01
Best way to test the decoder quality is decode an ADX, reencode it, and then decode it again and compare with the first decode (not just listening but calculate volume rms). Try all sample rates too.

Xiaopang
23-10-2007, 05:05
thats a good idea, but this only works if the encoder works at 100% efficiency. i just test listen to the waves and adx-files. if you can't hear any differences then the decode was ok. if you do, then you don't need to re-encode and decode them again, just to know that the decode sucked.

Eiji
10-11-2007, 19:57
The most accurate one I found was ADX_Conv.exe which was an ugly GUI based decoder, but gave perfect volume levels for all sample rates.

Could you upload this utility for me please?

Thanks.

Darkfalz
11-11-2007, 00:05
I included it in my dc_tools check the other thread.

Eiji
12-11-2007, 13:37
I got it, thanks!